[Metastatic lung tumor of a thyroid cancer origin detected by a periodic health examination--a case of a complete response].

Reports is the case of a 21-year-old student, who received a medical examination at our Department for an abnormal chest shadow that had been detected during a periodic health examination at his university. No special subjective symptoms such as a cough and/or sputa, pyrexia, pectoralgia, and dyspnea were noted. A thyroid tumor was palpable and a 99mTc thyroid scintigram and a 201Tl thyroid tumor scintigram gave cause to suspect thyroid cancer and a metastatic lung tumor. A total thyroidectomy and a right modified neck dissection revealed a tumor (histologically, a papillary cancer), 3.5 cm in diameter, that mainly involved the right lobe. It was found that 131I-100 mCi internal irradiation was very effective for the metastatic lung tumor, and no abnormal shadow was subsequently revealed by chest X-ray. Now, 6 years later, he is alive with no manifestations of a local relapse nor any abnormal chest X-ray findings.